Valve-operating mechanism



July 6 1926. 1,591,671

I W. B. FLANDERS v VALVE OPERATING MECHANISM Filed Jan. 26, 1923 r z PO-:3 M1"F 'VVTLB Flam den! ATTORN EY Patented July 6, 1926.

UNITED STATES PATENT OFFICE.

' HOUSE ELECTRIC AND MANUFACTURING SYLVANIA.

COMPANY, A- CORPORATION OF PENN- VALVE-OPERATING MECHANISM.

Application filed January 26, 1923. Serial No. 615,128.

My invention relates to admission valves for prime movers, moreparticularly for steam turbines, and it has for its object to provideoperating mechanism for opening and closing an admission valve of thischaracter which shall permit of relatively quicker closingthan openingmovement of the valve.

With prime movers of the relatively 3 larger sizes, such as largeturbines, owing .to the large inertia of moving parts, it is desirableto open the admission valves slowly in order to obtain an admission ofsteam which is commensurate with the acceleraa 5 tion of the movingparts. It is also dcsirable to limit the rate at which steam is drawnfrom the boilers. Too rapid an increase in the rate of steam flow tendsto cause priming of the boilers which-is dangerous. On the other hand,if it is necessary to stop the prime mover, it is desirable to quicklyshut otf the supply of steam; and this is particularly true when thesteam is cut. oil by an emergency over-speed device.

Apparatus embodying features of my iiivention is illustrated on theaccompanying drawing, forming a part of this application, in which thefigure is a diagrammatic sectional view of an admission valve and itsoperating mechanism showing my improvement applied thereto.

Referring now to the drawings for a more detailed description of myinvention, I show an admission valve, at 10, having a valve stem 11pivotally connected, at 12, to an operating lever 13, which has one endfulcrumed, at 14-,and the other end pivotally connected, at 15, to therod 16 of an op erating piston 17 arranged in an operating cylinder 18.

Motive fluid is admitted at the ends of the operating cylinder 18 bymeans of conduits 19 and 20 connected to pilot valve mechanism 21, thepilot valve having an operating stem 22 pivotally connected, at 23, to alever 24, which has one end pivotally connected, at 25, to the rod 16and the other end operatively connected, at 26, to a. suitable governor,at 27. The connection of the lever 24 with the rod 16 permits of theusual follow-up motion in response to a change in the governor position.

well-known t ply motive uid received. from a conduit 28 to opposite'endsof the operating cylinder 18 and to provide for the exhaust of motivefluid from opposite sides of the operating piston through the conduits19 and 20 andtlie exhaust conduits 29 and 30 to the exhaust line 31.

The .function of securing relatively quicker closing of the admissionvalve than the opening thereof is secured by means of valve mechanism,at 32, arranged in the conduit 19. This valve mechanism preferablycomprises a housing 33 having a seat 3st for a valve 35, which isarranged to open in the direction of the operating cylinder. A spring 36is located in the housing and it rests against the top of the valve inorder to maintain the latter against its seat. The valve 35 is providedwith a recess 37, which serves to afford communication between oppositesides of the valve even when it is fully seated. A suitable screw 38 iscarried by the lower portion of the housing-33 for the purpose ofaccurately limiting movement of the valve 35 toward its closing positionso as to prevent possible sticking or jamming thereof.

As the valve 35 opens toward'the operating cylinder 18, it will be clearthat it does not exert any appreciable effect on the admission of motivefluid to the upper end of the operating cylinder 18 to secure movementof the admission valve, at 10, toward a closing position, wherebyclosure of the valve may be quickly efl'ected. On the other hand, whenmotive fluid is admitted to the lower end of the cylinder 18 to securemovement of the admission valve to an open position, motive fluid whichis above the operating piston 17 is exhausted through the conduit 19;and, of course, the How is in such a direction as to permit the spring36 to hold the valve 35 against its seat 34. The recess 37, however,permits of the slow passage of fluid through the conduit 19,

whereby the operating piston 17 moves upward'slowly to secure a slowmovement of the admission valve, at 10, toward an open position.

It is to be understood that any suitable pe and it is adapted tosupmechanism may be employed in the conduit 19 which will function topermit the free flow of motive fluid therethrough to the operatingcylinder to secure a quick movement of the admission valve toward itsclosing position and which will permit of a restriction of the exhaustof motive fluid therethrough when the admission valve is being opened bythe operating piston. Also, the recess 37 may obviously be formed on theseat 34.

From the apparatus described, its operation will be clearly understood.Fluid under pressure is admitted to the operating cylinder by means ofthe pilot valve mechanism 21, w ich is moved initially in response tomovement of the governor 27. Thereafter, motive fluid is admitted byeither the conduit 19 or th conduit 20 to the operating cylinder 18 andexhausted from the latter at t e end opposite to that at which motivefluid is being admitted. Movement of the operating piston results, notonly in movement of the admission valve, but also of movement of thepilot valve of the pilot valve mechanism so as to bring the latter backto a neutral position when the admission valve takes up a positionsuitable to the position of the governor. The valve mechanism, at 32,serves to permit of the free flow of motive fluid through the conduit 19tothe operating cylinder 18 so as to secure movement of the operatingpiston 17 to move the admission valve, at 10, toward a closing position,whereby the supply of motive uid to the prime mover may be quickly cutoff. When pressure fluid is supplied to the cylinder 18 to securedmovement of the operating piston 17 in the other direction to move theadmission valve toward an open position, the valve mechanism, at 32,serves to permit a restricted exhaust of fluid therethrough so that theoperating piston moves relatively slowly in order to secure a slowopening of the admission valve 10, whereby the rate of admission ofsteam to a suitable motor, engine or turbine is increased a the inertiaof movable parts is overcome.

While I have shown my invention in but one form, it will be obvious tothose skilled in the art that it is not so limited, but is susceptibleof various other changes and modifications, without departing from thespirit thereof, and I desire, therefore, that only such limitationsshall be placed thereupon as are imposed by the prior art or as arespecifically set forth in the appended claims.

What I claim is:

1. Th combination with a prime-mover admission valve, of an operatingcylinder having motive fluid supply and exhaust connections at its ends,an operating piston in the cylinder and connected to the admissionvalve, and means associated with one of the connections to assurerelatively slower motion of the operating piston in one direction thanin the other, whereby the admission valve may be closed relativelyquicker than it may be opened.

2. The combination with a prime-mover admission valve, of an operatingcylinder having motive fluid inlet and exhaust connections at its ends,an operating piston in the cylinder which is connected to the admissionvalve, a valve in the connection which supplies motive fluid to theoperating cylinder to secure closing movement of the admission valve andwhich opens in the direction of the operating cylinder, said valve beingprovided with a. recess, whereby, when it closes upon motive fluid beingadmitted to the other end of the operating cylinder, it will permit ofthe relatively slow exhaust of fluid through its conduit to secure arelatively slow movement of the admission valve toward its openposition.

3. The combination with a prime-mover admission valve, of fluid-pressureoperated mechanism for moving the valve to open and closed positions,and means cooperating with said fluid-pressure operating mechanism,whereby said mechanism operates relatively more quickly in one directionthan in the other to secure a relatively quicker closing motion of thevalve than the opening motion thereof.

4. The combination with a prime-mover admission valve, of an operatingcylinder, an operating piston arranged in the cylinder and connected tothe admission valve, motive fluid supply and exhaust connectionsarranged at the ends of the cylinder, and a check valve provided in oneof the connections having a passage which permits of the flow of fluidwhen the valve is seated.

In testimony whereof, I have hereunto subscribed my name this 23rd dayof January, 1923.

WARREN B. FLANDERS.

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